Spark-plug combination tool



June 17 1924. 1,497,963

E. UNFRIED SPARK PLUG COMBINATION TOOL Filed Jan. 15 1923 INVENTOR Eugene vhf/566i F/ML ATTORNES- Patented June 17, 1924.

UNITED STATES I 1,491,953 PATENT OFFICE.

EUGENE UNFRIELD, OF WEST ORANGE, NEW JERSEY.

SPARK-PLUG COMBINATION TOOL.

Application filed January 15, 19 23. SerialNo. 612,666.

tact p0ints,a correct gage forming a part of my invention, and for polishing the contact points; and to produce such a handy tool in a simple and inexpensive manner.

Figures 1 and 2 are two front views of my invention, looking upon it from opposite sides; Fig. 3 is a piece of sheet-metal from which two tools, such as are shown in Figs. 1 and 2, are stamped out, and Fig. 4 is a portion of a spark-plug, partly in cross-section, showing how the gage, inserted between the contact points, is applied in practice.

Referring more particularly to Figs. 1 and 2, 1 is a metal tubing which may be seamless or have an open seam 2, when the tube is rolled from a piece of sheet-metal, the open seam being formed at the meeting of the two edges of the sheet-metal; the end 3 of the tubing 1 is cut to form a blade having one straight edge 4 and one spiral edge 5; both edges may be blunt, or one of them, or both, may be sharpened. In Fig. 1, the straight edge 4 and the extremity 6 of the blade 3 have knife edges. At one end of the tubing 1, a wire brush 9 is ailiXed and held in place by the compressed walls of the tubing 1. The semicircular disk 7 is fiat and tangent to the tubing 1; and 8 is the aperture made in the tubing 1 by the stamping out of the disk 7 therefrom.

Referring to Fig. 3, 10 and 11 are sections of a sheet-metal blank cut along the lines 6 5 6 and along the lines of semicircular disks 7. When such a section 10 or 11 is rolled into a cylinder, the edge 4 of the blank will become the straight edge 4, and the edge 5 of the blank will become the spiral edge of Figs. 1 and 2. The semicircular disks 7 will curl up during the rolling of the sheet into a cylinder, remainthe fol- I ing flat and becoming tangent to the cylinder, as shown in Figs. 1 and 2. Sometimes the disk 7 may be bent slightly further from its tangential position.

Referring to Fig. 4, 12 is the screw-end of the spark-plug 13; and 14, 15, are its contact points, separated by a gap. InFig. 4, this gap is filled by the disk 7 of tubing 1, which is in positionto be used as a gage. The disk 7 is slightly bent outward from the tangent position.

Any kind of metal tubing of proper thickness and hardness is adaptable. to my purpose, but I prefer to make the tubing by rolling a piece of sheet-metal into a cylinder, as shown in Figs. 1, 2, and '3, because of the ease, simplicity, and cheapness of this construction. The material must be hard and stiff. I prefer to use hard cold-r0lled steel. The thickness of the sheet must be equal to the proper distance between the contact points of the spark-plug, to secure a correct gage for the spark gap. Under prevailing practice, the standard gage is .025 inches. The outside diameter of the tubing, when it is a cylinder of circular cross-section, should be somewhere between the internal diameter 16 of the screw-end of the plug, and the diameter 17 of the rod which ends in the contact point 14, so that the blade 3 may be conveniently inserted between the internal walls of the plug and used to scrape the carbon 01f their surfaces. In practice, I find that a diameter of inches will give the tubing 1 and, therefore, the blade 3, the necessary curvature. It will be seen from Fig. 4, that the diameter of the disk 7 must be such as to allow the insertion of the disk between the contact vpoints, i. e. this diameter must be not greater than the diameter 16. The disk 7 serves not only as a gage but as a supporting surface for the thumb as the operator grasps the tube in order to scrape the spark plug, thus afi'ording means for exerting the pressure needed for eifective scraping, especially when, as is often the case, both the tool and the operators hand are greasy and difficulty is experienced in exerting pressure during the scraping act. The disk 7 need not be of semicircular form. It may be of any. suitable shape, provided the above-stated condition for insertion is satisfied. In order that the gage may be used on all types of plugs, its depth must be sufiicient to enable it to be inserted between the contact points of a tened tangentially thereto.

' 2. A spark-plug tool, comprising a metal tubing of thickness equal to the normal gap of said spark-plug, and a gage formed by a section partially cut from said tubing and flattened under an angle thereto.

3. A spark-plug tool made of sheet metal having a thickness equal to the normal gap of said spark-plug and rolled into a cylinder, and a flat portion of said sheet metal projecting from said cylinder and constitutin a a 'e for the a of said 5 arl lu a: 2:. c r;

4. In .a spark-plug tool, a tubing of a cross-section corresponding to the curvature of the internal surfaces of said spark-plug, and a flat disk, said tubing and said disk being made of a single piece of sheet-metal of thickness equal to the normal gap of said spark-plug.

5. A tool made of sheet-metal rolled into a cylinder and shaped to form a blade at one end thereof, a portion of said sheetmetal forming a flat disk tangential to said cylinder.

6. A spark-plug tool made of sheet-metal of thickness equal to the normal gap of said spark-plug and rolled into a cylinder whose curvature corresponds to the curvature of the nternal surfaces of said spark-plug, one

end of said cylinder being shaped to form a tapering blade having a straight scraping edge, a flat portion of said sheet-metal projecting from said cylinder, the surface dimensions of said projecting portion being such as to permit its insertion between the contact points of said spark-plug.

7 A spark-plug tool, comprising a tubing of sheet-metal of thickness equal to the normal gap of said spark-plug, and a semicircular disk partially cut from said tubing and flattened tangentially thereto, the diameter of said disk being not greater than the diameter of the internal surface of the screw-end of said sparkplug.

8. A tool made of sheet metal rolled into a cylinder, a portion of said sheet metal forming a flat disk at an angle to said cylinder.

9. A spark-plug tool, comprising a tubing made of hard cold-rolled steel of thickness equal to the normal gap of said sparkplug, the curvature of said tubing corresponding to the curvature of theinternal surfaces of said spark-plug, and a semi-circular disk partially cut from said tubing and flattened at an angletheret-o, the"d iameter of said disk being not greater than the diameter of the internal surface .oflthe screw-end of said spark-plug.

' 10. The combination with a blade of curved cross-section, of a flat disk, said blade and said disk being made of a'single piece of sheet metal.

11. The combination with a tapering blade of curved cross-section, of a fiat disk, said blade and said disk being made of a single piece of sheet metal'of predetermined thickness.

12. The combination with a blade having a cross-section of predetermined curvature, of a fiat disk-shaped gage, said blade and said gage being made of a single piece of sheet metal of thickness determined by said gage.

13. A spark plug tool, comprising a tubing made of hard cold-rolled steel of' thickness equal to the normal gap of saidspark plug, the curvatureof said tubing cb'rresponding to the curvature of the "internal surfaces of said spark plug, one end ofsa'id tubing being shaped to form a blade with one straight edge and the other edge-tapering towards the first one in a spiral, and a semi-circular disk partially cut from said tubing and flattened at an angle theretojto serve as a gage for said spark plug and as a support for the operators thumb.

EUGENE UNEBIED, 

